The invention relates to a lock, in particular for a motor vehicle containing a locking mechanism comprising a catch and a pawl for locking the catch in a ratchet position, a blocking lever (also referred to as a blocking pawl or latching pawl) for blocking the pawl in its ratchet position and a release lever for opening the locking mechanisms, in particular, by moving the blocking lever out of its blocking position and a blocking lever that blocks the locking mechanism at least in the event of acceleration forces of a predetermined magnitude occurring, for example in case of an accident (crash).
The motor vehicle door closure or simply referred to as a lock for a motor vehicle, comprises a locking mechanism with a rotatably mounted catch, accommodating a locking bolt, normally arranged on the motor vehicle and that is often also referred to as lock holder or lock bracket. The locking mechanism also contains a pawl for locking the catch in order to retain the locking bolt.
The catch of a motor vehicle door lock also contains a fork-like infeed slot (also referred to as an infeed section) formed by a load arm and a collecting arm, which is entered into by the locking bolt of a motor vehicle door or hatch, such as also a motor bonnet or tailgate, when the door or hatch is closed. The locking bolt then rotates the catch from an opening position in the direction of the closed position until the pawl locks the catch. The locking bolt can then not leave the inlet slot of the catch.
In previous years, motor vehicle locks have been established in which, due to a respective design of the latching surface, the catch can introduce an opening moment into the pawl if the pawl is in the latching position, i.e. the catch produces an opening moment in relation to the pawl. Such a lock requires a blocking lever for blocking the pawl in the detent position. The blocking lever must be pivoted or turned out of its blocking position for the pawl to be able to leave its ratchet position for opening of the locking mechanism. Such locks, known, for instance from DE 10 2008 061 524 A1 are particularly easy to operate and can, in particular, be opened with little force.
Motor vehicle door locks are available that contain two ratchet positions, a pre-ratchet and a main ratchet position. The pre-ratchet position serves to capture the respective door or bonnet if it does not reach the main ratchet during closing. If the catch is turned further from the pre-ratchet position, it finally reaches the main ratchet position.
A lock generally contains a release lever, required to open or unlatch a locking mechanism. Such a release lever is typically connected to a door or bonnet. It can be an external or an internal handle of the respective door. Where such a handle is activated, the release lever is activated or pivoted in order to release the locking mechanism and thus open the lock.
In the event of an accident or a vehicle collision, hereinafter also referred to as a crash, extremely high acceleration forces equal to a multiple of the earth's acceleration can suddenly be generated. As a result, the respective lock including the lever mechanisms, such as the actuation lever of the motor vehicle, is exposed to considerable gravitational forces, that could cause unintentional opening of the locking mechanism and thus opening of the associated lock. In the event of a crash, also the actuation lever, i.e. an internal or external lever can be unintentionally opened, which could also cause the locking mechanism to be opened. It must be ensured that such a lock cannot unintentionally open in such a situation.
Based on the described scenarios, vehicle users are exposed to considerable danger. An unintentionally opened motor vehicle door can no longer provide any integral safety equipment such as a side airbag or side impact protection for the protection of the passengers of the vehicle. For this reason certain measures have been implemented in the past which in the event of the occurrence of the described abnormal acceleration forces, i.e. in the event of a crash, either block the lock actuation or the locking mechanism. A so-called inertia lock can be provided, which is in its resting position under normal operating conditions and which is then not engaged in the locking mechanism/lever mechanism.
In order to ensure that a lock does not open unintentionally in the event of a crash, document EP 01 518 983 A2 discloses a lock with a locking mechanism, comprising at least one actuating lever for releasing or opening the locking mechanism, i.e. a release lever. The lock also contains a locking lever, safely blocking the actuating lever during specified vehicle accelerations.
Document DE 10 2011 010 816 A1 discloses a lock with a locking mechanism containing a catch and a pawl for locking the catch. The lock is a lock with an opening moment, able to move the catch into the pawl in the ratchet position. The lock also contains a blocking pawl or blocking lever for blocking the pawl in the ratchet position. The arrangement also features a release lever for opening or actuating the locking mechanism.
In the event of a crash particularly high accelerations occur compared to the usual opening operation. Where the actuating lever only blocks during high vehicle accelerations, as experienced in the event of a crash, unintentional opening of the locking mechanism in the event of a crash can be prevented. In case of a usual actuation of the door handle, the actuating lever is not blocked due to the high acceleration, allowing opening of the lock.
In the event of a crash, a bounce-back can occur as a result of the excessively high acceleration forces, also referred to as bouncing. A delayed or repeated bounce-back, coupled, in particular, with changes to the acceleration forces and directions can result in a failure of the blocking device in the event of high accelerations, aiming to prevent unintentional opening of the lock in the event of a crash.